Lawn mower sharpener



June 23?, 1936.. E, R Q 2,045,187

LAWN MOWER SHARPENER' Filed Aug. 4, 1934 I J vi/ENTDE IEHUED .ZZTTUENEYE- Patented June 23, 1936 I UNITED STATES PATENT OFFICE LAWN MOWER SHARPENER Thomas E. Hurd, Glendale, Calif. Application August 4, 1934, Serial No. 738,419

3 Claims. (01. 7682.1)

An object and feature of my invention is a clamp the two block sections firmly to the fixed lawn mower sharpener using a file, which file shaft or rod I2.

may be clamped on the fixed axle shaft common The end block sections 24 have the file supto most lawn mowers having rotating blades. porting block offset wider than the clamping A further object and feature of my invention block as indicated at 34, and this has a semi- 5 is attaching the file to blocks which may be circular recess 35. The purpose of this recess clamped to the non-rotating axle, these blocks is to accommodate the block on a projection on being slightly rotatable on the fixed axle to the housing structure l3 at the ends of the bring the file into and out of contact with the shaft I 2.

rotating blades so that the blades may be sharp- A lug 36 is secured to each end block assembly 10 ened by movement of the lawn mower as in cut- 24 and preferably to the block section carrying ting, or the file may be disengaged from the the file. Each lug has a tip end 3'! which extends blades when properly sharpened for using the beyond the end edge of the blocks and is prolawn mower in cutting grass. In addition, I vided with a threaded perforation 38 through have an adjusting means comprising set screws which extends a set screw 39, each set screw 35 operating through lugs on end blocks, these set being adapted to engage one of the sockets Id screws engaging a stationary part of the lawn on which the handle is mounted. The manner mower and thus being adapted for slightly tilting of adjusting the improved sharpener is as follows:

the blocks and the file. The blocks are attached to the axle I 2 sufii- My invention is illustrated in connection with ciently tight so that the blocks will not rotate 20 the accompanying drawing, in which: freely on this shaft but will have a considerable Fig. 1 is a vertical longitudinal section through frictional grip but may be rotated by applying the typical lawn mower showing the attachment suflicient force. The end of the set screw is of my invention. brought to bear against the sockets I 4 and is Fig. 2 is a perspective view of the attaching tightened, thus rotating the block assembly and 25 I blocks and the file. the file on the shaft l2. While this adjustment Fig. 3 is a detailed section on the line 33 is being made, if one of the blades I9 is posiof Fig. 2 in the direction of the arrows. tioned to engage the file and form the desired Referring to Fig. 1, this illustrates a typical contact between the file and the blocks, then lawn mower having wheels II, a fixed shaft l2, when the set screw is properly tightened, the 30 a housing structure l3 with sockets 14 to Which lawn mower may be advanced and the blades is connected a yoke I5 of the handle IS, a rotary rotated in their normal rotation of travel which shaft I! with a series of radial spokes l8 on the is counterclockwise relative to Fig. 1. This causes outer ends of which are the cutting blades I9. the blades to contact and rub over the exposed These blades operate in conjunction with a fixed surface of the file, thereby Sharpening the b 35 cutter blade 20 mounted on a support 2|. As the blades become worn in filing the set screw A feature of my invention is in mounting the 39 may be slightly adjusted to bring a proper sharpener in such a manner that when the lawn bearing Pressure between he bl es and the file.

mower is moved either over a lawn or a pave- When the blades are p p y sharpened a d 40 ment, the rotation of the blades will cause their it is desired to discontinue the sharpening action, 40 sharpening. it is not necessary to move the file and the sharp- In my invention I employ a sharpener assemener assembly as the set screw 39 may be loosbly designated by the numeral 22. This includes ened and the block 24 forcibly rotated in a clockcenter blocks 23 and a pair of end blocks 24. wise direction having reference to Fig. 1 on the Each of these block assemblies has a clamping fixed shaft l2 a sufiicient amount to leave a 45 block section 25 and a file supporting block secclearance between the edges of the blades I9 tion 26. This latter has a shallow groove 21 and the file. Each set screw may then be with shoulders 28 on each edge of the groove in brought into contact with one of the sockets M which is supported the file 29, this file being and thus will prevent rotation of the blocks 5 secured by screws 30 which are illustrated as havinto a position which might engage the blades ing countersunk heads. Each block section has and the file. The lawn mower may then be used a semi-circular opening 3| and they have a joint for cutting grass without removing the blocks 32, the block sections being clamped together by and the file. clamping screws or bolts 33. The joint should Various changes may be made in the details 5 have a slight clearance so that the bolts can of construction without departing from the spirit or scope of the invention as defined by the appended claims:

I claim:

1. A lawn mower sharpener comprising a plurality of split blocks having openings therethrough to engage a fixed shaft of a lawn mower, each block being thus divided into two substantially equal halves, clamping screws to clamp the two halves of each block to the shaft, one-half of each block having a shallow groove on an outer face, a file fitted in each of the shallow grooves and secured to each of the blocks whereby the blocks are connected together as a unit, and means to rotate the blocks and the file as a unit on the fixed shaft whereby the file may contact rotating blades on a lawn mower on a line closely contiguous to a plane containing the fixed shaft and the axis of rotation of the blades, the means to rotate the split blocks on the shaft comprising a. lug projecting from each end block and an adjusting set screw through each lug adapted to engage a fixed part of the lawn mower, to positively prevent rotation of the blocks due to sharpening contact of the blades and the file.

2. In a lawn mower sharpener in which a lawn mower has a fixed shaft, a rotating shaft with cutting blades thereon, a fixed structure at the opposite ends of the fixed shaft combined with a clamp formed with a plurality of split blocks, means to clamp said blocks to the fixed shaft, a file secured to said blocks and screw means interengaging the end blocks of the clamp and the fixed structure at the end of the fixed shaft to adjust the file to intersecting a plane drawn through the fixed shaft and the rotating shafts, whereby the blades in rotation contact the file closely contiguous to such plane.

3. In a device as described, in which a lawn mower is provided with fixed side structures, a rotatable shaft having cutting blades, a fixed shaft secured in the side structure, the said shafts being parallel combined with a sharpening assembly having a plurality of clamps, each substantially rectangular in longitudinal cross section, each clamp having a diametrical split block surrounding the fixed shaft and having an opening for the shaft and attached to the shaft by bolts, each clamp being thereby divided into two parts which are substantially equal, one part of each clamping block having a shallow groove, a file fitted in all the shallow grooves and secured to each of the clamping blocks, the file being therefore operative to space the clamping blocks on the fixed shaft, and means interengaging between the end blocks of the clamp and the fixed side structure of the lawn mower on opposite sides to rotate the clamps and hence the file to position the file to engage the rotating blades, the interengaging- THOMAS E. HURD. 

